FIG. 6.
Analysis of the survival of chickens infected with the BAC-derived MDVs carrying B-ZIP mutations in the Meq gene. Groups of 14-day-old line P (n = 12) or RIR (n = 9) birds were infected with 1,000 PFU of the RB-1B strain of MDV, BAC-derived pRB-1B5, or the mutant viruses pRB-1BHom/Hom and pRB-1BBZIP/BZIP and their revertant viruses. All birds were infected by intra-abdominal injection with the viruses. Shown are line P (A) and RIR (B) birds that did not suffer fatal MD expressed as a percentage of infected individuals.